Multiple-car elevator system



Aug. 3, 1954 w, F. EAMES MULTIPLE-CAR ELEVATOR SYSTEM 7 Sheets-Sheet 1Filed Feb. 1, 1952 Fig.2. Car Floor High Call Call FIOOI' Cm Cancel CullColl & m R 00 H M m ECI. O V mm fln .mf Wm WITNESSES: 4 @441 y 5% W. F.EAMES MULTIPLE-CAR ELEVATOR SYSTEM Aug. 3, 1954 7 Sheets-Sheet 2 FiledFeb. 1, 1952 INVENTOR WITNESSES: 67%

\villiom F.Edmes.

ATTORNEY Aug. 3, 1954 Filed Feb. 1, 1952 W. F. EAMES MULTIPLE-CARELEVATOR SYSTEM 7 Sheets-Sheet 4 Patented Aug. 3, 1954 UNITED STAiEfi ihiENT OFFICE MULTIPLE-CAR ELEVATOR SYSTEM Application February 1, 1952,Serial No. 269,503

12 Claims. 1

This invention relates to elevator systems, and it has particularrelation to an elevator system employing a bank of elevator cars whereinat least part of the elevator cars are conditioned under predeterminedcircumstances to reverse at an intermediate floor served by the elevatorcars.

In order to avoid unnecessary car travel and to expedite service tofioors of a building served by elevator cars, the elevator cars oftenare arranged to reverse at an intermediate floor. Although such reversalmay occur for a down-traveling elevator car, it is more commonlyencountered for lip-traveling elevator cars and will be discussed withreference to such cars.

In a bank of elevator cars, two or more elevator cars may be travelingup at the same time. If a leading up-traveling elevator car reaches afloor representing the highest call for elevator service, the arrival ofthe leading car cancels the call and conditions the leading car fortravel in the down direction. If no other calls are registered requiringfurther up travel of one of the trailing cars, the cancellation of thecall by the leading car results in a reversal of such trailing car. Thesimultaneous reversal of two or more elevator cars of the bank oftenresults in a poor distribution of elevator cars and impairment ofservice for certain floors of the building, particular the higherfloors, and particularly during periods of heavy down travel.

In accordance with the invention, the distribution of elevator cars andthe service for higher floors of the building are improved by preventingthe reversal of a trailing elevator car if a leading elevator carcancels the only registered call for service requiring further up travelof the elevator cars. Under such circumstances, one or more of thetrailing elevator cars may be forced to travel to the upper terminalfloor before it can be reversed. If a call for service is registeredbetween the trailing and leading elevator cars at the time the leadingelevator car cancels the highest call for service, a trailing elevatorcar may be conditioned for reversal at the highest of the intermediatecalls for service.

It is therefore an object of the invention to provide an improvedelevator system including a bank of elevator cars wherein at least partof" the elevator cars are conditioned to reverse when the farthest callin the direction of travel of the elevator cars has been reached.

It is a further object of the invention to provide a bank of elevatorcars wherein reversal of a leading elevator car at an intermediate floorconditions a trailing elevator car to continue in the same direction toa terminal floor.

It is also an object of the invention to provide a bank of elevatorcars, as defined in the preceding paragraph, wherein the presence of aregistered call for service intermediate the leading and trailingelevator cars conditions the trail ing elevator car to reverse at thefarthest of the intermediate calls for service.

Other objects of the invention will be apparent from the followingdiscussion taken in conjunction with the accompanying drawings, inwhich:

Figure 1 is a view in elevation with parts broken away of an elevatorsystem embodying the invention;

Fig. 2 is a view in elevation with parts broken away of a floor selectorsuitable for the system of Fig. 1;

Fig. 3 is a schematic view showing control circuits suitable for thesystem of Fig. 1;

Fig. 3A is a schematic view showing electromagnetic switches and relaysemployed in the circuits of Fig. 3. If Figs. 3 and 3A are placed inhorizontal alignment, it will be found that the respective contacts andcoils of the two figures are substantially in horizontal alignment.

Fig. i is a schematic View in straight line form showing iloor callcircuits suitable for the system of Fig. 1;

Fig. 4A is a schematic view showing electromagnetic switches and relaysemployed in the circuits of Fig. i. If Figs. 4 and 4A are placed inhorizontal alignment, it will be found that corresponding contacts andcoils of the two figures are substantially in horizontal alignment.

Fig. 5 is a schematic view in straight line form showing additionalcircuits suitable for the systern of Fig. l; and

Fig. 5A is a schematic view of electromagnetic switches and relaysemployed in the circuits of Fig. 5. If Figs. 5 and 5A are placed inhorizontal alignment, it will be found that corresponding coils andcontacts of the two figures are substantially in horizontal aligrment.

The invention is suitable for banks of elevator cars including variousnumbers of cars serving buildings having various numbers or floors.However, the invention may be discussed adequately for a bani; ofelevator cars having four cars A, B, C and D, serving a building havingseven floors.

Inasmuch as the elevator cars of the bank have similar control circuits,it will suffice to discuss the control circuits for the elevator card.

Similar components for the remaining elevator cars are identified by thesame reference characters preceded by the letter corresponding to theappropriate elevator car. For example, the reference character Edesignates the slowdown inductor relay for the elevator car A, whereasthe reference character BE designates the slowdown inductor relay forthe car B.

Electromagnetic relays and switches employed in the elevator system mayhave break contacts which are closed when the relays and switches aredeenergized and dropped out. Also, the relays and switches may have makecontacts which are closed when the switches and relays are energized andpicked up. Break contacts are open when the switches and relays areenergized and picked up, whereas make contacts are open when theswitches and relays are deenergized and dropped out.

In order to distinguish the sets of contacts employed for each relay,each set will be designated by the reference character for the relayfollowed by the numeral corresponding to the specific set of contacts.For example, th reference character U3 designates the third set ofcontacts for the up switch U.

In order to facilitate the consideration of the invention, the followingapparatus is listed:

Apparatus for car A- VHigh-speed relay UUp switch DDown switch GInductorholding relay ESlowdown inductor relay E -Stopping inductor relaylVl-Car running relay WUp-direction preference relay X-Down-directionpreference relay H-I-ligh car-call relay TCar-call stopping relaySFloorcall stopping relay K-Hig'h floor-call relay LAuxi1iary highfloor-call relay N-Lockout relay JReversing relay Apparatus common toall cars- ZUR to iURUp call-storing relays 'ZDR to iDR-Down call-storingrelays Figure 1 Fig. 1 shows the mechanical arrangement of various partsof the elevator system. In Fig. 1, a cable ll! passes over a sheave lland has its ends attached respectively to the elevator car A and to acounterweight l2. The sheave H is secured to the shaft is of a drivingmotor i i. A conventional spring-applied electromagneticallyreleasedelevator brake l5 is associated with the shaft of the motor IS.

in the operation of the elevator cars, certain contacts are made orbroken as each elevator car reaches predetermined positions in itshoistway. Although each elevator car may actuate suitable switcheslocated in the hoistway, it is common practice to provide a floorselector for this purpose. A typical fioor selector i6 is illustratedfor th car A.

The floor selector It has a brush carriage H on which suitable brushesare mounted for movement relative to contact segments in accordance withmotion of the elevator car. In Fig. 1 two brushes 32 and iii areillustrated which coact respectively with rows of contact segments b2,etc., and 92, etc. The arrangement of the contact segments will bediscussed further in connection with Fig. 2.

Th brush carriage I? may be reciprocated in accordance with movement ofthe elevator car, but at a much slow-er rate, by means of a screw H;which is coupled to the shaft l3 through suitable gearing.

The elevator cars may be of the automatic type which are controlledentirely by passengers desiring elevator car service. However, forpresent purposes, it will be assumed that elevator cars are of theattendant-operated type. Thus, the elevator car A has a switch CS whichis operated by the car attendant to engage a contact CSl when theelevator car is to start. The elevator car also has a number of car-callpush buttons 20 to lo. The numeral for each car-call push-buttonreference character designates the floor with which the push button isassociated. Thus, if a passenger desires to be discharged at the seventhfloor, the car attendant would press the push button To.

A slowdown inductor relay and a stopping inductor relay F are employedin conditioning the elevator car A to stop at a floor. When the elevatorcar is to stop at a floor, the coil for the slowdown inductor relay E isenergized. Such energization does not result in pickup of the breakcontacts El and E2 until the elevator car reaches predeterminedpositions wherein the inductor relay is adjacent a magnetic inductorplate UEP or DEP. One of the inductor plates UEP is provided for each ofthe floors at which the elevator car A is to stop during up travel. Whenthe elevator car is a predetermined distance from a floor at which it isto stop, the up-inductor plate UEP for the floor is adjacent theinductor relay E and completes a magnetic circuit for opening the breakcontacts El. Such opening initiates a slowdown of the elevator car.

In a similar manner, a down-inductor plate DEP is provided for eachfloor at which the elevator car is to stop during down travel. When theelevator car approaches a fioor at which it is to stop, the inductorplate DEP completes a magnetic circuit for the inductor relay E to openthe break contacts E2 and initiate a slowdown of the elevator car A.

In a somewhat similar manner the stoppinginductor relay F cooperateswith up inductor plates UFP and down-inductor plates DFP to bring theelevator car to a stop at any desired floor. Thus, when the elevator carapproaches a floor at which it is to stop when traveling in the updirection, one of the inductor plates U'FP completes a magnetic circuitfor the inductor relay to open the break contacts Fl. If the elevatorcar is traveling in a down direction, one of the inductor plates DFPcooperates with the inductor relay to open the break contacts F2 a shortdistance in advance of the floor at which the elevator car is to stop.Such inductor relays are well known in the art.

Calls for elevator car service from passengers located at Various floorsserved by the elevator cars are registered by suitable push buttonslocated at the various floors. For example, at the second floor, an uppush button 2U may be operated to register a call for up elevator carservice. A similar push button would be located at each floor from whichup elevator car service is desired. Each up push button is identified bythe reference character U preceded by a numeral corresponding to thefloor at which the push button is located. Each up push button is commonto all of the elevator cars. In an analogous manner, a down push button(identified by the letter D preceded by a numeral corresponding to thefloor at which the push button is located) is located at each hall orfloor from which down elevator car service is .desired. The down-callpush button 2D is illustrated in Fig. 1 for the second floor.

Figure 2 Fig. 2 shows in greater detail the arrangement of the contactsegments, brushes, switches, employed in the floor selector I6. RelaysH, T, S, K, L, which are associated with the floor selector are shown inother figures.

As the elevator car A moves upwardly, a brush 30 mounted on the brushcarriage l'l successively engages contact segments a2-to al. This brushhas a length sufficient to bridge successive contact segments and isemployed in controlling a high car-call relay H. A brush 3l mounted onthe brush carriage also engages successively the contact segments tocontrol a car-call stopping relay T during up travel of the elevator carA. The numeral employed in each contact segment reference characterdesignates the floor with which the contact segment is associated.

During up travel of the elevator car A, a brush 32 on the brush carriagel'l successively engages contact segments b2 to 136 to control afloorcall stopping relay S.

During up travel of the elevator car A, a brush 33 successively engagescontact segments 02 to 06 for the purpose of cancelling floor calls forwhich the elevator car stops.

During up travel of the elevator car, a brush 34 mounted on the brushcarriage successively engages contact segments dl to (Z6 for the purposeof controlling a high floor-call relay K and an auxiliary high callrelay L. The brush 34 has a length suificient to bridge successivecontact segments.

During down travel of the elevator car A, a brush ll mounted on thebrush carriage successively engages contact segments fl to 1'2 for thepurpose of cancelling down floor calls answered by the elevator car.

During down travel of the elevator car A, a brush 42 mounted on thebrush carriage ll successively engages contact segments gl to 9 2 forthe purpose of controlling the floor-call stopping relay S.

During down travel of the elevator car A, a brush 43 mounted on thebrush carriage l'l successively engages contact segments he to M for thepurpose of controlling the car-call stopping relay T.

During up travel of the elevator car A, a cam 49 successively opensnormally closed mechanical switches 52 to 56, which are associatedrespectively with the second to the sixth floors. The cam 49 has alength sufficient to bridge the operating members of successiveswitches. These switches are employed in controlling the energization ofthe high call-car relay H.

Figure 3 Fig. 3 shows various control circuits for the elevator system.Although various motor drives may be employed for the system, it will beassumed that a drive of the variable-voltage type is employed. In such adrive, the motor I4 is a direct-current motor which has its armature MAenergized from the armature GA of a directcurrent generator GE. Thedirect-current generator is rotated at a constant rate by a suitablemotor (not shown). The armatures MA and GA, together with a generatorseries fiield winding GS, are connected by a circuit 22 in series in aloop circuit. The field winding HF for the motor I4 is connecteddirectly to a source of direct current represented by the buses L-|-3and L3.

The release coil for the brake I5 is connected for energization acrossthe buses L+3 and L-3 either through make contactsUl of an up switch ormake contacts D2 of a down switch.

The direction of travel of the elevator car A is determined by thepolarization of the generator field winding GF. When the make contactsDI and D3 of the down switch are closed, the generator field winding isconnected through a resistor Rl across the buses L+3 and L-3 forenergization with proper polarity for down travel of the elevator car.If the generator field winding is connected through the resistor RI andthe make contacts U2 and U3 of the up switch across the buses L+3 andL3, the polarity of energization of the field winding is suitable for uptravel of the elevator car. Maximum speed of the elevator car isobtained by shunting the resistor RI through make contacts VI of a speedrelay.

For up travel the speed relay V is energized through break contacts Elof the slowdown inductor relay, normally-closed contacts of an uppercam-operated limit switch VTU and make contacts U4 of the up switch. Ifthe elevator car is to slow down adjacent a floor at which it is tostop, the break contacts El of the slowdown inductor relay open todeenergize the speed relay V. Also, if the car reaches its upper limitof travel, a cam opens the limit switch VTU to deenergize the speedrelay.

For down travel, the speed relay V is energized through break contactsE2 of the slowdown inductor relay, normally-closed contacts of acamoperated lower limit switch VTD and make contacts D4 of the downswitch. If the elevator car is to slow down as it approaches a fioor atwhich it is to stop, the break contacts E2 open to deenergize the speedrelay. If the car nears its lower limit of travel, a cam opens the lowerlimit switch VTD to deenergize the speed relay,

By manipulation of his car switch CS, a car attendant controls theinitial energization of a car running relay M and. either the up switchU or the down switch D. The relays and switches can be energized only ifcertain safety devices 23 are in their safe conditions. These safetydevices may include contacts which are closed only if the varioushoistway doors and the car doors are closed.

It will be assumed that the elevator car stops automatically in responseto registered car calls and registered floor or hall calls. If theelevatorcar is conditioned for up travel, make contacts WI of theup-direction preference relay are closed, and the following circuit isestablished by operation of the car switch:

L+3, CS, CSl, Wl, Fl, STU, U, M, 23, L3

This conditions the elevator car for up travel. It will be noted thatenergization of the up switch U results in closure of the make contactsU5 to establish a holding circuit around the car switch and the contactsWI Consequently, stopping of the elevator car is independent of thecondition of the car switch.

When the elevator car A approaches a floor at which it is to stop, thestopping inductor relay finally opens its break contacts Fl to deener- 7size the up switch U and the car running relay M. As the elevator carnears its upper limit of travel, a cam opens the normally-closed limitswitch STU to deenergize the up switch U and the car running relay M.

If the elevator car is conditioned for down travel, the make contacts XIof a down-direction preference relay are closed. An operation of the carswitch completes the following circuit:

L+i, CS, CS1, XI, F2, STR, D, M, 23, L3

Operation of the down switch D closes make contacts D5 to complete aholding circuit around the car switch and the contacts XI.

If the down-traveling elevator car approaches a iioor at which it is tostop, the stopping inductor relay finally opens its break contacts F2 todeenergize the down switch D and the car running relay M. As theelevator car nears its lower limit of travel, the normally-closed limitswitch STD is opened by a cam to assure deenergization of the downswitch D and the car running relay.

The coils of the inductor relays E and F, and the coil of an inductorholding relay G are energized through make contacts M of the car runningrelay, and any one of three sets of make contacts. Thus, if the elevatorcar is to stop in response to a car call, the make contacts Tl close toenergize the coils. If the elevator car is to reverse at an intermediatefloor, the make contacts J l of the reversing relay close to energizethe coils. If the elevator car is to stop in response to a registeredfloor or hall call, the make contacts Si of the floor call stoppingrelay close x to energize the coils. When the inductor holding relay Gis once energized, it closes its make contacts GI to establish a holdingcircuit until the contacts Mi of the car running relay open. Theenergization of the stopping inductor relay F also is controlled bybreak contacts V2 of the speed relay.

The Lip-direction preference relay W can be energized only if theelevator car is not traveling down (break contacts D5 are closed), theelevator car is not conditioned for down travel (break contacts X2 areclosed), the reversing relay is not energized (break contacts J2 areclosed), and the elevator car is not adjacent its upper limit of travel(normally-closed cam-operated switch SQT is closed) The up-directionpreference relay W, when once energized, is deenergized in either of twoways. As the elevator car reaches its upper limit of travel, a cam opensthe normally-closed limit switch SGT to deenergize the up-directionpreference relay. In addition, if the elevator car is to reverse at anintermediate floor, the break contacts J 2 of the reversing relay open.Consequently, as the elevator car comes to stop at the intermediatefloor, the make contacts M2 of the car running relay open to completethe deenergization of the up-direction preference relay.

The down-direction preference relay X can be energized only if theelevator car is not traveling up (break contacts US are closed), theup-direction preference relay W is not energized (break contacts W2 areclosed), and the elevator car is not adjacent its lower limit of travel(limit switch 55313 is closed). When once energized, the downdirectionpreference relay can be deenergized only as it nears its lower limit oftravel. Under such circumstances, a cam opens the normally-closed limitswitch 30B to deenergize the down-direction preference relay.

Figure 4 Fig. 4 shows the circuits for controlling the up call-storingrelays, the down call-storing relays and the floor-call stopping relayS.

When the second floor up call button 2U is pressed, the up call-storingrelay EUR. is connected across the buses L+3 and L3. As a result of itsenergization, the relay closes its make contacts ZURi to establish aholding circuit around the push button 2U. It will be noted that thecontact segments for all of the cars which control the stopping ofup-traveling elevator cars at the second floor are connected to the busL+3 through the make contacts ZURI. These contact segments include, forexample, the contact segments 112 for the car A and the contact segmentsBbZ for the car B. Contact segments for additional cars would besimilarly connected.

If the elevator car A is traveling up, make contacts W3 of theup-direction preference relay are closed, and when the brush 32 reachesthe contact segment b2, the following energizing circuit is completed:

L+3, ZURi, b2, 32, W3, S, L3

The floor-call stopping relay now is energized to initiate the stoppingof the elevator car A at the second floor. If another of the elevatorcars, such as the car B, had been the first car to near the second floorwhile traveling up, a stepping operation thereof would be initiated in asimilar manner.

If a stopping operation of the elevator car A at the second floor isinitiated, the brush 33 engages the contact segments 02 and completesthe following circuit:

L+3, ZURQ, ZURN, c2, 33, W4, G2, L-3

The resulting energization of the cancelling coil ZURN cancels the callat the second floor. The coil for the relay EUR and the coil ZURN may bewound in opposition so that the energization of the cancelling coil BURNresults in resetting of the relay ZUR. Had another one of the elevatorcars, such as the car B, been the first to answer the call of the secondfloor, the cancelling coil ZURN would have been energized through I thecorresponding contact segment for such car.

It will be understood that a similar up call-storing relay and a similarcancelling coil would be associated in the same manner with each of theup call push buttons.

If a prospective passenger at the second floor presses the down-callpush button 2D, the down car-storing relay 2BR is connected forenergization across the buses L- -t and L3. This relay closes its makecontacts 2BR! to establish a holding circuit around the push button.Contact segments for all of the elevator cars of the bank, such as thecontact segment 92 for the car A and contact segment B 2 for the car B,now are connected through the contacts ZDR! to the bus L+3.

The first elevator car to approach the second floor while traveling downnow completes an energizing circuit for its floor-call stopping relay.For example, if the elevator car A is the first to near the second fioorwhile traveling down, the brush 42 engages the contact segment 92 tocomplete the following circuit:

L-3, ZDRI, g2, 42, X3, S, L3

The energization of the floor-call stopping relay prepares the elevatorcar to stop at the second floor.

Following the initiation of the stopping operation at the second floor,the elevator car A has its brush 4| engage the contact segment f2 tocomplete the following circuit:

The resulting energization of the cancelling coil 2DRN resets the downcall-storing relay ZDR in the same manner discussed for the relay ZUR.Had the elevator car B been the first to stop at the second floor, itwould have completed a similar cancelling circuit through the contactsegment Bf2.

If one of the elevator cars, such as the elevator car A while travelingup is conditioned to stop and reverse in response to a down floor call,a cancelling circuit for the down floor call is completed for theelevator car A through the contacts J3 and W5 which then shunt thecontacts X4.

Each of the down floor or hall call push buttons has a similar downcall-storing relay and a similar cancelling coil associated therewith inthe same manner.

Figure 5 The upper part of Fig. 5 shows circuits for controlling thehigh car-call relays and the carcall stopping relays. Each of thecar-call push buttons to To normally is open. However, when pressed,each button is held in its pressed condition until the elevator carreverses its direction of travel. Thus, each of the buttons may beconstructed of magnetic material, and when pressed, may be maintained inits pressed condition by means of a holding coil 200 to Ice. The holdingcoils are connected in series across the buses L+3 and L3, eitherthrough make contacts WT or the make contacts X6 of the preferencerelays. These contacts both are momentarily open to reset the car-callpush buttons when the elevator car reverses its direction of travel.

Each of the car-call push buttons for the intermediate floors whenoperated connects two contact segments to the bus L+3. Thus, th car-callpush button 20, when pressed, connects the contact segments a2 and 7L2to the bus L+3. The elevator car does not have passengers desiring theseventh floor during down travel, and consequently only one contactsegment a! need be connected through the car-call push button To to thebus L+3.

If the elevator car A is traveling up, and if a car call is registeredfor the fourth floor, the brush 3| engages the contact segment a4 apredetermined distance in advance of the fourth floor to energize thecar-call stopping relay T through the circuit:

L+3, 40, a4, 3!, WG, T, M4, L3

The car-call stopping relay then would initiate a stopping operation ofthe elevator car. The parts may be so related that the brush 3| leavesthe contact segment shortly before the elevator car comes to a fullstop.

If the elevator car A were traveling down with a passenger to bedischarged at the fourth floor, the following circuit would be completedas the elevator car nears the fourth floor:

L+3, 40, H4, 43, X5, T, M4, L3

Consequently, the car-call stopping relay T again would be energized toinitiate the stopping operation of the elevator car A at the fourthfloor. The

10 parts may be so related that the brush 43 leaves the contact segmenth4 shortly before the elevator car comes to a full stop.

The high car-call relay 1-1 when energized indicates the presence of aregistered car call for a floor above the position of the elevator car.The mechanical switches 52 to 56 are employed in controlling theenergization of this high car-call relay. It will be noted that one ofthe mechanical switches is connected across each successive pair ofcontact segments. The mechanical switches connected to the contactsegments corresponding to the position of the elevator car or to thefloor directly below the elevator car are opened by the cam :29 toprevent energization of the high carcall relay H through car-call pushbuttons for the lower floors. However, if any car-call push button ispressed for a floor above the position of the elevator car, a circuit iscompleted for the high car-call relay H through the intermediatemechanical switches. Thus, with the elevator car at the third floor, asshown in Fig. 5, if a car call is registered for the sixth floor, thefollowing circuit would be completed.

The car-call circuits are standard in the art.

The reversing relay J is energized in order to reverse the direction ofthe elevator car at an intermediate floor. For the specific systemherein shown, the reversing relay J is effective only during up travelof the elevator car. For the relay to be energized, no car calls must beregistered for a floor above the position of the elevator car (breakcontacts HI are closed), the car must be traveling up (make contacts W8are closed), no other elevator car is conditioned to reverse at anintermediate floor and no floor call is registered for a floor above theposition of the elevator car (make contacts Kl are closed), and thelockout relay N is deenergized (break contacts N! are closed).

The high floor-call relay K, together with the auxiliary high floor-callrelay L are controlled in part from a call above indicator circuit 50.This circuit includes break contacts for all of the call-storing relaysconnected in series. The contacts are so arranged that those associatedwith call-storing relays requiring up travel of the elevator car arelocated above the point of contact of the brush 34 with the contactsegments d! to 15. The order in which the contacts are connected and thepoints of contact to the circuit 52 of the contact segments d! to (16may be ascertained by inspection of Fig. 5. Such call above indicatorcircuits are well known in the art. It will be understood that each ofthe contact segments dl to dit is connected to each of the correspondingcontact segments for other elevator cars in the bank.

The high floor-call relay K can be energized only if no floor call for afloor above the position of the elevator car is registered (all breakcontacts of the call-storing relays above the position of the brush 34are closed), the elevator car A is traveling up (make contacts W3 areclosed), no other elevator car of the bank is conditioned to reverse atan intermediate floor (break contacts BKZ, CK3 and DK3 are closed), andthe lockout relay N is deenergized (break contacts N2 are closed).

The auxiliary high floor-call relay L can be energized only if no floorcall is registered requiring up travel of the elevator car (breakcontacts for the call-storing relays associated with floors ll above theposition of the brush a l are all closed), and if the elevator car A istraveling up (make contacts W9 are closed).

The lockout relay N is intended to prevent reversal of the car A at anintermediate floor under certain conditions. For the lookout relay N tobe energized, the elevator car A must be traveling up (make contacts Wit are closed). In addition, the car A must not be conditioned forreversal at an intermediate iioor (break contacts K3 are closed).Furthermore, no floor call must be registered requiring up travel of theelevator car (make contacts L! are closed). Finally, floor call must beregistered for a floor above the position of at least one other of theelevator cars (make contacts BLZ, GL2 or DL2 are closed). If theseconditions all obtain, the lookout relay N picks up and closes its makecontacts N3 to establish a holding circuit. The holding circuitmaintains the lookout relay N energized until the elevator car A reachesits upper terminal floor whereupon contacts W9 of the up-directionpreference relay open. As long as the lookout relay N is energized, thebreak contacts Ni are opened to prevent a reversal of the car A at anintermediate floor. Also, opening of the break contacts N2 preventsenergization of the high floor-call relay K.

Operation It is believed that an understanding of the invention will befacilitated by a brief review of a typical operation of the elevatorsystem. it will be assumed initially that the elevator cars are locatedat the lower terminal floor and that a down floor call is registered forthe sixth floor. By reference to Fig. 4, it will be noted that theregistration of the floor call is eiiected by pressing the push buttonSD which energizes the down call-storing relay BDR. The downcall-storing relay closes its make contact tDRi to establish a holdingcircuit around the push button an and to connect the contact segmentsgfi and corresponding segments for the remaining cars to the bus -1-3,As shown in Fig. 5, the down callstoring relay 6BR also opens its breakcontacts EDRZ to prevent energization of the high floorcall relay K andof the auxiliary high floor call relay L.

Since the elevator car is at the lower terminal floor, the limit switchBQE (Fig. 3) is open, and the down-direction preference relay isdeenergized. Also, the upper limit switch 331 closed, and theup-direction preference relay W is energized.

The elevator car attendant now operates the car switch CS and closes thedoors of his car to complete the following circuit:

L+3, CS, CSl, W1, Fl, STU, U, M, 23-, L3

Energization of the car running relay M has no immediate effect on theoperation of the system. However, the up switch U closes its makecontacts Ui to release the brake is. Closure of make contacts U2 and U3connects the generator field winding G? with proper polarity for uptravel of the elevator car, and the elevator car starts in an updirection. Make contacts Ud close to energize at the speed relay Vthrough the limit switch VTU and the contacts El or the slowdowninductor relay. The speed relay thereupon closes its make contacts V! toshunt the resistor RE and permit full speed operation of the elevatorcar. Also, the speed relay opens its break contacts V2 to preventenergization of the stopping inductor relay F. 7

Closure of the make contacts U5 establishes a holding circuit around thecar switch and the contacts Wi. The car switch now may be released.Break contacts Ut open to prevent energization oi the down-directionpreference relay X.

As the elevator car A in its upward travel passes the fourth floor, itwill be assumed that the elevator car B starts from the lower terminalfloor. The sequence for starting the elevator car B will be understoodfrom the foregoing discussion of the starting of the elevator car A.

Turning now to Fig. 5, it will be noted that as the elevator car Aapproaches the sixth floor the brush 3 finally engages the contactsegment (16 which connected to the call above indicator circuit 5% abovethe open contacts GDRZ. Since none of the other elevator cars is assumedto be in condition to reverse at an intermediate floor, the breakcontacts BKZ, CK3, and DKS are closed. Also, the lookout relay N isassumed to be de energized and its contacts N2 are closed. Consequently,the high floor-call relay K is energized through the circuit:

L+3, 'JDRZ, BURZ, d6, 34, W9, K, 3K2, CK3, DK3,N2,L3

It will be noted that the auxiliary high floor-call relay L also isenergized.

As a result of its energization, the high floorcall relay K closes itsmake contacts KI to complete an energizing circuit for the reversingrelay J. It is assumed that no car call is registered for a floor abovethe position of the elevator car A and that the break contacts H! areclosed.

The high floor-call relay K, in addition, opens its break contacts incircuit with the high floorcall relays for the remaining elevator cars.For example, the contacts K2 open to prevent energization of the highfloor-call relay BK for the carB.

The high floor-call relay K opens its break contacts K3 to preventenergization therethrough of the lookout relay N. Consequently, theelevator car A now is conditioned to stop and reverse at the sixthfloor.

As a result of its energization, the reversing relay J closes its makecontacts J 2 to establish a holding circuit around the contacts Ki. Inaddition, the reversing relay closes its make contacts J i (Fig. 3) toenergize through the contacts Ml the coils of the inductor holding relayG and the inductor relay E.

Upon energization, the inductor holding relay G closes its make contactGt to establish a holding circuit around the contacts J I. In addition,make contacts G2 (Fig. 4) close while the elevator car is stilltraveling up to answer a call, and such closure completes the followingcall-cancelling circuit:

L-l-3, SDRi, GDRN, s, $1, J3, we, o2, L-s

The cancelling of the call causes the relay EDR to drop to itsdeenergized position wherein the self-holding contacts GDR! are open.The break contacts GDRZ (Fig. 5) close and energize the relays K and L.Energization of the relay K and closure of contacts Ll have no immediateeiiect on the operation or" the system. Contacts L2 close to prepare therelay .BN for subsequent energization.

It is assumed that the elevator car B at this time is traveling up pastthe second floor, and that no corridor calls are registered for floorsbetween the positions of the elevator cars A and 3. Under the assumedconditions, the following energizing circuit for the relay BL isestablished upon closure of the break contacts 6DR-2:

If any of the other elevator cars of the elevator system are conditionedfor up travel at the same time, the corresponding relays, such as therelay CL or the relay DL, may be similarly energized and picked up underthe assumed conditions.

The effect of energization and pickup of the relay BL will be consideredbelow following completion of the discussion of the operation of theelevator car A which is now nearing the sixth floor.

Referring to Fig. 1, the coil of the slowdown inductor relay E for theelevator car A now is energized. When the inductor relay reaches theup-inductor plate UEP for the sixth floor, the magnetic circuit iscompleted which results in opening of the break contacts E I The openingof the break contacts El deenergizes the speed relay V (Fig. 3).Consequently, the make contacts VI open to introduce the resistor RI inseries with the generator field winding GF. This slows the elevator carA to a landing speed. In addition, break contacts V2 open to energizethe coil of the stopping-inductor relay F through the contacts GI and MIUpon continued movement of the elevator car towards the sixth floor, thestopping-inductor relay F (Fig. 1) reaches the up-inductor plate UEP forthe sixth floor to complete a magnetic circuit which results in openingof the break contacts Fl. The opening of these contacts deenergizes theup switch U (Fig. 3) and the car running relay M.

As a result of its deenergization, the up switch U opens its contacts UIto deenergize the coil of the brake l and to permit the spring-appliedbrake to move into braking condition. In addition, the contacts U2 andU3 open to deenergize the generator field winding. The elevator car nowstops at the sixth floor The up switch U opens its make contacts U4 andU5, and closes its break contacts U6. Such contact operations have noimmediate effect on the system. The deenergization of the car runningrelay M results in opening of the make contacts Ml to deenergize thecoils of the inductor holding relay G and of the inductor relays E andF. Also, make contacts M2 open. Since the reversing relay has, alreadyopened the break contacts J 2, it follows that the up-directionpreference relay W now is deenergized. Opening of the make contacts M3(Fig. 5) has no immediate effect on the operation of the system.

The deenergization of the up-direction preference relay results inopening of the make contacts WL, W3, W4, W5, W6, W1, W8, W9 and Wlilwithout immediate effect on the operation of the system. However, theclosing of the break contacts W2 (Fig. 3) completes an energizingcircuit for the down-direction preference relay X through the lowerlimit switch 35B and the recently-closed break contacts U6 of the upswitch.

The down-direction preference relay X closes its make contacts XI, X3,X5 and X5 to prepare the elevator car for operation in the downdirection. Opening of the break contacts X2 (Fig. 3) preventsenergization of the Lip-direction preference relay W. Closure of themake contacts X4 (Fig. 4) completes through the recently closed contactsM3 of the car running relay, the following cancelling circuit:

14 As a result of the continued energization of the cancelling coilBDRN, the down floor call for the sixth floor is held cancelled untilthe car leaves the floor on its down trip.

It will be recalled that the relay BL was energized followingcancellation of the sixth floor call. Upon energization, the auxiliaryhigh floorcall relay BL closes its make contacts associated with thelookout relays of the other elevator cars, such as the contacts BLZ,which are associated with the lockout relay N of the car A. However,since contacts K3 are open at this time, the closure of the contacts BL2has no effect on relay N of the elevator car A.

At the time the relay BL closes its contacts BLI the break contacts BK3are also closed (since the contacts K2 are open at such time, the relayBK cannot be energized. Inasmuch as the make contacts L2 also areclosed, the following circuit is established:

L+3, L2, BLI, BK3, BN, BWID, L3

Consequently, the relay BN closes its make contacts BN3 to establish aholding circuit which is interrupted only when the elevator car reachesthe upper terminal floor. In addition, break contacts BNI are opened toprevent energization therethrough of the reversing relay BJ for the carB. Consequently, the car B must proceed to the upper terminal floor andcannot reverse at an intermediate floor. The contacts BN2 open toprevent energization therethrough of the high floor-call relay BK. Whenthe elevator car B reaches the upper terminal floor, the up-directionpreference relay BW is deenergized as a result of opening of the upperlimit switch B30T (Fig. 3). Due to such opening, the contacts BWIO (Fig.5) open to deenergize the lookout relay BN.

Next, it will be assumed that immediately prior to the cancellation ofthe down floor call at the sixth floor by the elevator car A, a downfloor call was registered at the fourth floor. Such registration waseffected by the pressing of the button 4D (Fig. 4) to energize the downcall-storing relay 4BR. This relay closed its make contacts 4DRI toestablish a self-holding circuit and to connect the contact segment 94and corresponding contact segments of the other cars to the bus L+3. Inaddition, the registered call resulted in opening of the break contacts4DR2 (Fig. 5). It will be noted that this registered call is for a floorintermediate the leading car A and the trailing car B.

Since the elevator car B is below the floor corresponding to the opencontacts 4DR2 at the time the call at the sixth floor is cancelled, theauxiliar high floor-call relay BL cannot be energized through the callabove indicator circuit 50. Therefore, the make contacts BLI remain openand the locking relay BN cannot be energized. As the up-travelingelevator car B nears the fourth floor, an energizing circuit for thehigh floor-call relay BK is established as follows:

Consequently, the relay BK closes its contacts BKI to complete under theassumed conditions an energizing circuit for the reversing relay BJ. Thereversing relay initiates a stopping and reversing of the elevator carat the fourth floor in the same manner by which the elevator car A waspreviously stopped and reversed at the sixth floor by the reversingrelay J. It will be noted that the energized high floor-call relay BKalso opens its contacts associated with the high floorcall relays of theremaining cars to prevent energization of such relays. As an example,the break contacts BKZ open to prevent energization of the highfloor-call relay K for the car A.

Finally, it should be noted that the break contacts BK3 open to preventenergization of the lookout relay BN.

From the foregoing, it is clear that if a leading up-traveling car stopsand reverses at an intermediate floor, and no calls for service areregistered for a floor above the position of a trailing up-travelingelevator car, the trailing uptraveling elevator car is conditioned tocontinue traveling in the up direction, in this case to the upperterminal floor. However, if at the time of the reversal of the leadingup-traveling elevator car, a call for a floor above the position of atrailing up-traveling elevator car exists, such as a floor call for afloor intermediate the positions of the two cars, the trailing elevatorcar is conditioned to proceed to the highest call for service and isstopped and reversed at the floor corresponding to such highest call forservice.

Although the invention has been described with reference to certainspecific embodiments there of, numerous modifications falling within thespirit and scope of the invention are possible. For this reason, thespecific embodiments herein set forth are to be construed in anillustrative rather than a limiting sense.

I claim as my invention:

1. In an elevator system, a structure having a plurality of floors, aplurality of elevator cars, means mounting the elevator cars formovement relative to the structure to serve the floors, callregisteringmeans for registering calls for elevator service for the floors,translating means responsive to arrival of each of the elevator carsadjacent the farthest floor in the direction of travel of the elevatorcar for which a call for service i registered for preparing the arrivingelevator car for reversal, and conditioning means responsive to arrivalof one of the elevator cars adjacent the farthest floor in the directionof travel of the elevator car for which a call is re istered forrendering the translating means of certain of the elevator carsinefiective for preparing said certain of the elevator cars forreversal.

2. In an elevator system, a structure having a plurality of floors, aplurality of elevator cars, means mounting the elevator cars formovement relative to the structure to serve the floors, callregisteringmeans for registering calls for elevator service for the floors,translating means responsive to arrival of each of the elevator carsadjacent the farthest floor in the direction of travel of the elevatorcars for which a call for service is registered for preparing thearriving elevator car for reversal, and conditioning means responsive toarrival of one of the elevator cars adjacent the farthest floor in thedirection of travel of the elevator car for which a call is registeredfor rendering the translating means of certain of the elevator carsineffective for preparing said certain of the elevator cars forreversal, said conditioning means including means responsive to thepresence of at least one registered call for a floor intermediate aleading one and a trailing one of said elevator cars for conditioningsaid translating means of the trailing car for operation.

3. In an elevator system, a structure having a plurality of fioors, aplurality of elevator cars, means mounting the elevator cars formovement relative to the structure to serve the floors, callregisteringmeans for registering calls for elevator service for the floors,translating means responsive to arrival of each of the elevator carsadjacent the farthest floor in the direction of travel of the elevatorcar for Which a call for service is registered, and condtioning meansresponsive to arrival of one of the elevator cars adjacent the farthestfloor in the direction of travel of the elevator car for which a call isregistered for rendering inefiective the translating means of certain ofthe elevator cars, the direction of travel of said certain of theelevator cars remaining unchanged until a predetermined terminal flooris reached by said certain of the elevator cars.

4. In an elevator system, a structure having a plurality of floors, aplurality of elevator cars, means mounting the elevator cars formovement relative to the structure to serve the floors, upcallregistering means operable for registering calls for elevator upservice from th floors, down call-registering means operable forregistering calls for elevator down service from the floors, controlmeans for causing the elevator cars during up travel to stopsuccessively at floors for which up calls are registered as the carsreach such floors, said control means being effective during up travelof the elevator cars for stopping the elevator cars at an intermediatefloor in response to a registered down call provided no call requiringfurther up travel of the elevator cars is registered, and conditioningmeans responsive to said stopping of one of the elevator cars during anup trip at an intermediate floor in response to a registered down callfor requiring certain of the elevator cars to travel to a higher floor.

5. In an elevator system, a structure having a plurality of floors, aplurality of elevator cars, means mounting the elevator cars formovement relative to the structure to serve the floors, upcall-registering means operable for registering calls for elevator upservice from the floors, down call-registering means operable forregistering calls for elevator down service from th floors, controlmeans for causing the elevator cars during up travel to stopsuccessively at floors for which up calls are registered as the carsreach such floors, said control means being efiective during up trave1of the elevator cars for stopping the elevator cars at an intermediatefloor in response to a registered down call provided no call requiringfurther up travel of the elevator cars is registered, and conditioningmeans responsive to said stopping of one of the elevator cars during anup trip at an intermediate floor in response to a registered down callfor requiring certain of the elevator cars to travel to a higher floor,the control means including reversing means responsive to said stoppingof the elevator car at a floor in response to the registered down callfor conditioning the elevator car for down travel.

6. In an elevator system, a structure having a plurality of floors, aplurality of elevator cars, means mounting the elevator cars formovement relative to the structure to serve the floors, upcall-registering means operable for registering calls for elevator upservice from the floors, down call-registering means operable forregistering calls for elevator down service from the floors, controlmeans for causing the elevator cars during up travel to stopsuccessively at floors for which up calls are registered as the carsreach such floors, said control means being efiective during up travelof the elevator cars for stopping the elevator car at an intermediatefioor in response to a registered down call provided no call requiringfurther up travel of the elevator cars is registered, and conditioningmeans responsive to said stopping of one of the elevator cars during anup trip at an intermediate floor in response to a registered down callfor requiring certain of the elevator cars. to travel to a higher floor,said conditioning means being rendered inefiective to control a trailingup-traveling elevator car in response to the presence of a registeredcall for a floor intermediate the trailing elevator car and an elevatorcar leading the trailing elevator car.

7. In an elevator system, a structure havin a plurality of floors, aplurality of elevator cars, means mounting the elevator cars formovement relative to the structure to serve the floors, upcall-registering means operable for registering calls for elevator upservice from the floors, down call-registering means operable forregistering calls for elevator down service from the floors, controlmeans for causing the elevator cars during up travel to stopsuccessively at floors for which up calls are registered as the carsreach such floors, said control means being effective during up travelof the elevator cars for stopping the elevator cars at an intermediatefloor in response to a registered down call provided no call requiringfurther up travel of the elevator cars is registered, and conditioningmeans responsive to said stopping of one of the elevator cars during anup trip at an intermediate floor in response to a registered down callfor requiring certain of the elevator cars to travel to a higher floor,said conditioning means being rendered inefiective to control a trailingup-traveling elevator car in response to the presence of a registeredcall for a floor intermediate the trailing elevator car and an elevatorcar leading the trailing elevator car, and said conditioning means beineffective for stopping the trailing elevator car in response to aregistered down call provided no call requiring further up travel of thetrailing elevator car is registered.

8. In an elevator system, a structure having a plurality of floors, aplurality of elevator cars, means mounting the elevator cars formovement relative to the structure to serve the floors, upcall-registering means operable for registering calls for elevator upservice from the floors, down call-registering means operable forregistering calls for elevator down service from the floors, controlmeans for causing the elevator cars during up travel to stopsuccessively at floors for which up calls are registered as the carsreach such floors, said control means being efiective during up travelof the elevator cars for stopping the elevator cars at an intermediatefloor in response to a registered down call provided no call requiringfurther up travel of the elevator cars is registered, and conditioningmeans responsive to said stopping of one of the elevator cars during anup trip at an intermediate floor in response to a registered down callfor requiring certain of the elevator cars to travel to a higher floor,said conditioning means being rendered ineffective to control a trailingup-traveling elevator car in response to the presence of a registeredcall for a fioor intermediate the trailing elevator car and an elevatorcar leading the trailing elevator car, said conditioning means beingeffective for stopping the trailing elevator car in response to aregistered down call provided no call requiring further up travel of thetrailing elevator car is registered, and the control means includingreversing means responsive to said stopping of the trailing elevator carat a fioor in response to the registered down call for conditionin thetrailing elevator car for down travel.

9. In an elevator system, a structure having a plurality of floors, aplurality of elevator cars, means mounting the elevator cars formovement relative to the structure to serve the floors, firstcall-registering means operable for registering calls for elevatorservice in a first direction from the floors, second call-registeringmeans operable for registering cal for elevator service in a seconddirection from the floors, control means for causing each of theelevator cars during travel in the first direction to stop successivelyat each of the floors approached by each of the elevator cars for whicha call is registered by the first call-registering means, said controlmeans ineluding translating means effective for initiating a stoppingand reversal of each of the elevator cars during travel in the firstdirection at an intermediate one of said floors reached by such elevatorcar for which a call is registered by the second call-registering meansprovided no call is registered by the first call-registering means forsuch intermediate floor and provided further that no call is registeredby the first and second call-registering means for a floor beyond suchintermediate floor in the first direction, and conditioning meansresponsive to said initiation of a stopping and reversal of one of theelevator cars for renderin ineifective the translating means for certainof the elevator cars.

10. In an elevator system, a structure having a plurality of floors, aplurality of elevator cars, means mounting the elevator cars formovement relative to the structure to serve the floors, firstcall-registering means operable for registering calls for elevatorservice in a first direction from the floors, second call-registeringmeans operable for registering calls for elevator service in a seconddirection from the floors, third callregistering means for each of theelevator cars operable for registering calls for floors desired for theload within each of the elevator cars, control means for causing each ofthe elevator cars during travel in the first direction to stopsuccessively at each of the floors approached by each of the elevatorcars for which a call is registered by the third call-registering meansfor such approaching elevator car or by the first call-registeringmeans, said control means including translating means effective forinitiating a stopping and reversal of each of the elevator cars duringtravel in the first direction at an intermediate one of said floorsreached by such elevator car for which a call is registered by thesecond call-registering means provided no call is registered by thefirst call-registering means for such intermediate floor and providedfurther that no call is registered by the third call-registering meansof the elevator car reaching such intermediate fioor or by the first andsecond callregistering means for a floor beyond such intermediate floorin the first direction, and conditioning means responsive to saidinitiation of a stopping and reversal of one of the elevator cars forrendering ineffective the translating means for certain of the elevatorcars.

11. In an elevator system, a structure having a plurality of floors, aplurality of elevator cars, means mounting the elevator cars formovement relative to the structure to serve the floors, firstcall-registering means operable for registering calls for elevatorservice in a first direction from the floors, second call-registeringmeans operable for registering calls for elevator service in a seconddirection from the floors, third callregistering means for each of theelevator cars operable for registering calls for floors desired for theload within each of the elevator cars, control means for causing each ofthe elevator cars during travel in the first direction to stopsuccessively at each of the floors approached by each of the elevatorcars ior'which a call is registered by the third call-registering meansfor such approaching elevator car or by the first callregistering means,said control means including translating means efiective for initiatinga stopping and reversal of each 'of the elevator cars during travel inthe first direction at an intermediate one of said floors reached bysuch elevator car forwhicha call-is registered by the second callifgi'sterin'g' means provided no call is registered by the fiijstcall-registering means for such 'interm'ediat e'fioor and providedfurther that no call is registered by the third "call-registering meansof-the elevator car reaching such intermediate fioor 'orfby the firstand'second callregistering nieans-for"a-floor beyond such intermediate"fioor the first direction; and conditioning means-responsive to saidinitiation of a stopping' and reversal of cheer the elevator cars forrendering inefl'ective-the translating means for certain of the elevatorcars, said conditioning means, in'response to the presence or a callregistered by the first or second call-registering means'for a floorintermediate the elevator car for which said stopping and reversal isinitiated and a trailing elevator car, being rendered ineffective tocontrol said trailing elevator car.

12. In an elevator system, a structure having a plurality of floors, aplurality of elevator cars, means mounting the elevator cars formovement relative to the structure to serve the floors, firstcall-registering means operable for registering calls for elevatorservice in a first direction from Lil 20 the floors, secondcall-registering means operable for registering calls for elevatorservice in a second direction from the floors, third call-registeringmeans for each of the elevator cars operable for registering calls forfloors desired for the load within each of the elevator cars, controlmeans for causing each of the elevator cars during travel in the firstdirection to stop .successively at each of the floors approached by eachof the elevator cars for which a call is registered by the thirdcall-registering means for such approaching elevator car. or by thefirst callregistering means, said control means including translatingmeans effective for initiating a stopping and reversal of each of theelevator cars during travel in the first direction at an intermediateone of said floors reached by such elevator car for which a call isregistered by the second call-registering means provided no call isregistered by the first call-registering means for such intermediatefloor and provided further that no call is registered by the thirdcall-registering meansof the elevator car reaching such intermediatefioor-or by the first and second-callregistering means for a floorbeyond such intermediate floor in the first direction,-and,-conditioning means responsive to said initiation of a stopping andreversal of one of the elevator cars for rendering ineffective thetranslating means for certain of the elevator cars; said conditioningmeans; in response to the-presence of-acall reg-, istered by the firstorsecond call registering means'for' a floor intermediate the elevator carfor which'said stopping and reversal is initiated and a trailingelevator car, being rendered inef-' fective to control said trailingelevator car, said conditioning means being effective for initiating astopping and reversing of the trailing elevator car at an intermediatefloor approached by the trailing elevator car for which a call isregistered by the second call-registering means, provided no call isregistered by the third call-registering means for such trailingelevator car or by the first or second call-registering means for afloor beyond the last-named intermediate floor in the first direction orby the first call-registering means of the last-named intermediatefloor.

No references cited.

